Electrical busway joint with self-adjusting braces

ABSTRACT

A busway system is provided. The busway system includes a first electrical busway section, a second electrical busway section, and a busway joint. The first and second electrical busway sections are disposed longitudinally offset from each other. The busway joint couples the first and second busway sections. The busway joint includes a first assembly coupled to the first busway section, a second assembly coupled to the second busway section, a plurality of conductors coupled to the first and second assemblies, a first movable brace coupled to the conductors, and a first brace locator coupled to the movable brace. The first and second assemblies move relative to each other between a collapsed position and an extended position. The first movable brace moves longitudinally along a length of the conductors. The first brace locator locates the first movable brace at a first position when the first assembly is in the extended position.

BACKGROUND

The field of the invention relates generally to an electrical busway,and, more particularly, to a variable length busway joint withself-adjusting braces joining electrical busway sections.

Elongated rectangular flat conductive busbar members are conventionallyinsulatively arranged within electrical busway sections for transportingmulti-phase high current electric power through industrial, commercial,and/or residential establishments. Successive elongated busway sectionsare electrically connected or interlocked together in end-to-endrelation to provide electrical continuity between a power source and apower consuming load.

When longitudinally aligned busway sections are electricallyinterconnected in a conventional installation, a self-contained buswayjoint is typically employed. To preserve the thermal properties of theindividual busway sections, the busway joint is conventionallyconstructed with electrically conductive splice plates and interleavinginsulative plates fixedly held together by electrically insulated bolts.

Busway sections are generally manufactured and distributed in the formof pre-manufactured fixed-length sections, so that a number of suchelectrical busway joints are used to install an extended length buswayrun in an industrial facility. A busway joint enables two fixed-lengthbusway sections to electrically connect at a distance different than thefixed length of the busway sections.

In many cases, the fixed-length sections do not match the specificlength required for a given installation. As a result, custom lengthbusway joints may be manufactured, adding significant cost and time tothe installation. For example, installers typically order non-standardor custom length busway sections or joints to complete an installation.The custom length busway sections typically are manufactured to aspecified length and the installer has to wait until it is delivered tofinish installation of the busway run.

It would be desirable to provide a busway joint or busway section havingan adjustable length to cooperate with adjacent longitudinally alignedbusway sections to eliminate the need for custom length busway sections.Additionally it would be desirable to provide an adjustable lengthbusway joint that permits replacement of a single busway section in arun without the need to remove other abutting busway sections from theend-to-end relationship. It would also be desirable to provide alongitudinally adjustable busway joint.

BRIEF DESCRIPTION

In one aspect, a busway system is provided. The busway system includes afirst electrical busway section, a second electrical busway section, anda busway joint. The first and second electrical busway sections aredisposed longitudinally offset from each other. The busway joint couplesthe first and second busway sections. The busway joint includes a firstassembly coupled to the first busway section, a second assembly coupledto the second busway section, a plurality of conductors coupled to thefirst and second movable assemblies, a first movable brace coupled tothe conductors, and a first brace locator coupled to the movable brace.The first and second movable assemblies move relative to each otherbetween a collapsed position and an extended position. The first movablebrace moves longitudinally along a length of the conductors. The firstbrace locator locates the first movable brace at a first position whensaid first assembly is in the extended position.

In another aspect, a busway joint coupling a first busway section and asecond busway section is provided. The busway joint includes a firstassembly coupled to the first busway section, a second assembly coupledto the second busway section, a plurality of conductors coupled to thefirst and second assemblies, a first movable brace coupled to theconductors, and a first brace locator coupled to the first movablebrace. The first and second assemblies move between a collapsed positionand an extended position. The first movable brace moves longitudinallyalong a length of the conductors. The first brace locator locates thefirst movable brace at a first position when the first assembly is inthe extended position.

In yet another aspect, a method for assembling a busway system thatincludes a first busway section, a second busway section disposedlongitudinally offset from the first busway section, and a busway jointis provided. The method includes coupling the first busway section to afirst assembly of the busway joint, adjusting a length of the buswayjoint, and coupling a second busway section to a second assembly of thebusway joint. The busway joint is movable between a collapsed positionand an extended position. A brace locator of the busway joint locates amovable brace of the busway joint at a first position when the buswayjoint is in the extended position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an example busway system in anunconnected state according to one embodiment.

FIG. 2 is a perspective view of the busway system shown in FIG. 1 withthe busway joint removed for clarity.

FIG. 3 is a perspective view of an example busway joint that may be usedwith the system shown in FIG. 1.

FIG. 4 is a cross sectional view of an example movable assembly of thebusway joint shown in FIG. 3.

FIG. 5 is a partial side plan view of an example movable assembly and aplurality of busbars of the busway joint shown in FIG. 3.

FIG. 6 is a perspective view of an example busbar that may be used withthe busway joint shown in FIG. 3.

FIG. 7 is a top plan view of an example splice plate and fork bar thatmay be used with the busway joint shown in FIG. 3.

FIG. 8 is a cross sectional view of example splice plates and fork barsthat may be used with the busway joint shown in FIG. 3.

FIG. 9 is a cross sectional view of example splice plates of a buswayjoint, such as the busway joint shown in FIG. 3.

FIG. 10 is a partial perspective view of another example busway joint.

FIG. 11 is a partial perspective view of another example busway joint.

FIG. 12 is a partial perspective view of another example busway joint.

FIG. 13 is a perspective view of an example busway joint that may beused in the busway system shown in FIG. 1.

FIG. 14 is an exploded view of an example adjustment assembly that maybe used with the busway joint shown in FIG. 13.

FIG. 15 is a side perspective view of the busway joint shown in FIG. 13without the cover and the stationary assembly.

FIG. 16 is another perspective view of the busway joint shown in FIG.13.

FIG. 17 is a perspective cross sectional view of an example vise bracethat may be used with the busway joint shown in FIG. 13.

DETAILED DESCRIPTION

As used in this description and in the claims which follow, the term“phase” shall be taken to include all conductors in different runs ofany particular busway, bus duct, or busway joint which carry the sameelectrical phase, and including those conductors which are used to carryany neutral or ground phase.

Various embodiments disclosed herein provide adjustable busway jointsfor busway systems. As used herein, a “busway joint” refers to a portionof a busway system (e.g., a joint, section, fitting, etc.) that isselectively extended and collapsed to fit between two or more portionsof the busway system. For example, the busway joint may be coupledbetween two sections of the busway system. In another example, thebusway joint may be coupled between a joint such as an elbow joint and asection of the busway system. The busway joints are installed andsecured in place to prevent the busway joint from moving. Theembodiments also describe techniques for securing internal conductorswhile maintaining electrical connection, such as using a compressiveforce.

According to an example embodiment, as shown in FIG. 1, a busway system110 includes an elongate first busway section 111, and an elongatesecond busway section 112 joinable in a substantially longitudinallyaligned, end-to-end relationship between an electric power source (notshown) and a load (not shown) via a separate removable andlongitudinally adjustable busway joint 113. Busway joint 113 is shown asan example and may be replaced with the busway joints described herein.In one embodiment, busway system 110 is configured to connect to aconventional 3-phase electrical distribution system (not shown). Inother embodiments, busway system 110 may be configured to connect withan electrical distribution system having any number of AC electricalphases. In still other embodiments, busway system 110 may be configuredto connect with a DC electrical distribution system.

In the example embodiment, as shown in FIG. 2, first busway section 111includes an elongate busway housing 161 and a plurality of runs ofgenerally flat elongate busbars 116A, 116B, and 116C positioned withinbusway housing 161. In this embodiment, each of busbars 116A-116C areassociated with a specific electrical phase of an electricaldistribution system, and are configured for operable connection with acorresponding phase, ground, or neutral bus within the electricaldistribution system. In other embodiments, each of busbars 116A-116C mayinclude a plurality of electrically coupled busbars, each set beingassociated with a specific electrical phase, ground, or neutral of theelectrical distribution system.

Similarly, in this embodiment, second busway section 112 includes anelongate housing 162 and a plurality of runs of generally flat elongatebusbars 126A, 126B, and 126C, positioned within housing 162. Each ofbusbars 126A-126C are associated with a specific electrical phase of anelectrical distribution system, and are configured for operableconnection with a corresponding phase, ground, or neutral bus within theelectrical distribution system. In other embodiments, each of busbars126A-126C may include a plurality of electrically coupled busbars, eachset being associated with a specific electrical phase, ground, orneutral of the electrical distribution system.

While first and second busway sections 111, 112 are shown in the figuresand discussed herein as each including three busbars, it should beunderstood that other embodiments are not so limited and first andsecond busway sections 111, 112 may each include any desired number ofbusbars and any desired number of busbars per electrical phase, ground,or neutral that enables busway system 110 to function as describedherein.

As illustrated in FIG. 2, in the example embodiment, busway sectionhousing 161 includes a busway top cover 121 and a busway bottom cover122 that cooperate with a pair of opposing busway side covers 127. Insome embodiments, busway housing top and bottom covers 121, 122 may eachinclude a respective busway top and bottom cover transition portion121A, 122A. Respective busway top and bottom cover transition portions121A, 122A are configured to cooperate with a housing 163 of buswayjoint 113. Busway housing 161 may be formed of rigid non-ferrousmaterial such as aluminum. When operatively installed, busway top cover121 and busway bottom cover 122 are configured to be fixedly coupledwith a respective top surface 123 and a bottom surface (not shown) ofbusway joint 113. In various embodiments, top cover 121 and bottom cover122 may be fixedly coupled with respective top surface 123 and thebottom surface of busway joint 113 via any means, such as fastening,riveting strapping, bolting, gluing, and the like that enables thebusway system to function as described herein. For example, each buswayhousing 161, 162, top cover 121, and bottom cover 122 may be fixedlycoupled to respective busway joint top surface 123 and the bottomsurface with a fastener such as a bolt (not shown). Busway housings 161,162 are arranged to prevent ingress of dust and contaminants into aninterior of respective busway sections 111, 112 and to operably preventinadvertent contact with electrically live busbars 116A-116C, 126A-126Cby a user. Busway housing 162 may be identical to busway housing 161.Busway housing side covers 127 may be fixedly coupled to respectivebusway top cover 121 and bottom cover 122 via any means, such asfastening, riveting strapping, bolting, gluing, and the like thatenables the busway system to function as described herein. For example,busway side covers 127 may be fixedly coupled to respective busway topcover 121 and bottom cover 122 with a fastener such as a bolt (notshown).

With reference to FIGS. 3-9, an example busway joint 200 for use in abusway system such as busway system 110 (shown in FIG. 1) is described.In the example embodiment, busway joint 200 includes a pair of opposedmovable assemblies 210, 211 (i.e., housing 163), a plurality ofelectrically conductive busbars 230, and one or more braces 250.Adjusting movable assemblies 210, 211 enables busway joint 200 to couplebusway sections 111, 112 over a range of different offset distances.Busbars 230 are separated into a plurality of phases. Busbars 230 indifferent phases are mutually isolated from each other. Each busbar 230may not be insulated from other busbars 230 within the same phase. Inother embodiments, busway joint 200 may include additional, fewer, oralternative components to couple busway sections 111, 112. Althoughbusway joint is shown as a longitudinally extending joint, busway joint200 may have a different configuration (e.g., an elbow joint, an anglejoint, etc.).

Movable assemblies 210, 211 include a plurality of electricallyconductive splice plates 212, a plurality of insulation laminations 214,one or more insulative spacers 216, and a cover 218. Each movableassembly 210, 211 is electrically coupled to a busway section (e.g.,busway sections 111, 112, shown in FIG. 1) and busbars 230. Movableassemblies 210, 211 are slidably coupled to busbars 230 to facilitateselectively adjusting the length of busway joint 200. In someembodiments, splice plates 212 and busbars 230 may be switched such thatmovable assemblies 210, 211 may be slidably coupled to splice plates212. In the example embodiment, movable assemblies 210, 211 areadjustable between a collapsed position and an extended position. In thecollapsed position, movable assemblies 210, 211 are prevented frommoving towards one another. In the expanded position, movable assemblies210, 211 are prevented from moving away from one another. In otherembodiments, at least one of movable assemblies 210, 211 may be fixedlycoupled to busbars 230.

Movable assemblies 210, 211 are configured to extend to a predeterminedposition (i.e., to couple the busway sections together) between theextended and the collapsed positions. Movable assemblies 210, 211 arefurther configured to maintain the predetermined position. In at leastsome embodiments, movable assemblies 210, 211 are configured to movesymmetrically (i.e., as movable assembly 210 moves, movable assembly 211moves a substantially equal and opposite distance). In otherembodiments, movable assemblies 210, 211 are configured to moveasymmetrically or independent of one another.

Splice plates 212 are configured to electrically couple to busbars 230and the busway sections. Although in electrical communication, spliceplates 212 and busbars 230 are separate components vertically and/orhorizontally offset from each other to facilitate length adjustment ofbusway joint 200. Splice plates 212 are made of an electricallyconductive material or combination of materials, such as aluminum orcopper. In the example embodiment, each busbar 230 is disposed betweentwo vertically stacked elongated splice plates 212 as described herein.For example, busway joint 200 includes three busbars 230, and buswayjoint 200 includes six splice plates 212 such that each busbar 230 isinterleaved between two splice plates 212. In other embodiments, spliceplates 212 may be in a different configuration.

In the example embodiment, insulation laminations 214 are elongatedlaminations spaced apart to receive busbars 230 and splice plates 212.Insulation laminations 214 are configured to prevent electrical currentfrom traveling between adjacent busbars 230 within movable assemblies210, 211. Electrical current traveling between busbars 230 may cause ashort circuit event (e.g., voltage and current spikes) that may causedamage to the busway system and systems coupled to the busway system.

In the example embodiment, spacers 216 are positioned adjacent to spliceplates 212 and busbars 230 to provide additional insulation andstructural support to movable assemblies 210, 211. Spacers 216 areformed from a rigid insulative material. In at least some embodiments,spacers 216 include grooves, slots, or other features to receive spliceplates 212 and busbars 230. Spacers 216 may also include apertures orthreaded holes configured to receive fasteners or other retainingmembers.

Cover 218 is configured to at least partially cover movable assemblies210, 211. Cover 218 is configured to prevent ingress of dust andcontaminants (e.g., water) into an interior of movable assemblies 210,211, and to prevent inadvertent contact by a user with the conductorstherein. In at least some embodiments, cover 218 may be configured toprovide an electrical grounding connection. In one embodiment, cover 218is formed of a rigid non-ferrous material such as aluminum.

FIG. 4 is a cross sectional view of movable assembly 210. In at leastsome embodiments, insulation laminations 214 include one or moreinsulative sheets 220 stacked together. In the illustrated embodiment,each insulation lamination 214 includes two or three insulation sheets220. In other embodiments, insulation laminations 214 may include adifferent number of insulation sheets 220. With reference now to FIG. 5,insulation sheets 220 may be offset to extend a creepage path 219between adjacent busbars 230. Extending the creepage path 219facilitates increased resistivity between busbars 230 to prevent shortcircuit events.

Insulation laminations 214 are spaced apart to define a plurality ofgaps 222. Gaps 222 are sized to fit splice plates 212, spacers 216, andbusbars 230. In the example embodiment, the width of each gap 222 issubstantially filled by splice plates 212, spacers 216, and busbars 230.A pair of opposed spacers 216 are positioned substantially adjacent toeach busbar 230. Filling gaps 222 prevents contaminants from affectingbusbars 230 and busbar 230 from moving within gaps 222.

In the example embodiment, spacers 216 include one or more apertures 224for receiving bracing fasteners 226. Bracing fasteners 226 may include,for example, screws, bolts, pins, or a different type of fastener.Bracing fasteners 226 may be a conductive material (e.g., a metal) or aninsulated material (e.g. rubber or plastic). Bracing fasteners 226 areconfigured to clamp splice plates 212, insulative laminations 214,spacers 216, and busbars 230 together within movable assemblies 210,211. Attaching bracing fasteners 226 through spacers 216 and not busbars230 enables busway joint 200 to be mechanically supported by movableassemblies 210, 211. In addition, attaching bracing fasteners 226through spacers 216 facilitates improved thermal dissipation withinbusbars 230.

In the example embodiment, bracing fasteners 226 are further configuredto selectively apply a compressive force inwardly towards a top and/or abottom insulation lamination 214 to clamp splice plates 212 and busbars230 together. Alternatively, spacers 216 may have a height greater thanthe combined height of splice plates 212 and busbars 230. In such anembodiment, bracing fasteners 226 may apply the compressive force whilefacilitating longitudinal adjustment of busway joint 200. Thecompressive force may also be applied to cover 218. The compressiveforce may prevent movable assemblies 210, 211 from moving with respectto busbars 230. In certain embodiments, fasteners 226 may be configuredto adjust the compressive force. For example, fasteners 226 may berotated to adjust the compressive force. In some embodiments, fasteners226 may be adjusted to remove the compressive force. Removing orsubstantially reducing the compressive force may enable movableassemblies 210, 211 to move with respect to busbars 230. In one example,busway joint 200 is installed by adjusting movable assemblies 210, 211to couple between busway sections and subsequently tightening bracingfasteners 226 to secure busway joint 200 in place.

FIG. 6 is a perspective view of an example busbar 230. Busbar 230 isformed from an electrically conductive material such as copper oraluminum. Busbar 230 is configured to facilitate electrically couplingtwo busway sections together. Each busbar 230 in a busway joint (e.g.,busway joint 200 shown in FIG. 3) may be associated with a differentpower phase. In some embodiments, busbar 230 may include a coating suchas epoxy to maintain electrical clearance between each phase of busbars230 and ground. In some embodiments, busbar 230 may include aninsulative or protective coating such as rubber to prevent an operatorfrom contacting busbar 230. Additionally or alternatively, busbar 230may include a conductive coating (e.g., plating) for facilitatingelectrical transmission between busbar 230 and splice plate 212.

In the example embodiment, busbar 230 includes a pair of opposed forkbars 232 coupled to splice plates 212. Fork bars 232 are electricallyconductive to transfer current from busbar 230 to splice plates 212.Although not shown in FIG. 6, another splice plate 212 is coupled toeach fork bar 232 such that forks bars 232 are positioned between spliceplates 212. In one embodiment, fork bars 232 are integrally formed withbusbar 230. In other embodiments, fork bars 232 are coupled to busbar230. Although referred to as “fork bar 232”, is it to be understood thatfork bar 232 may also include different configurations other than theillustrated embodiment with a pair of extending members and two openchannels between the members. For example, fork bar 232 may include aclosed channel coupled to splice plates 212.

Fork bars 232 are slidably coupled to splice plates 212 to permitmovable assemblies (e.g., movable assemblies 210, 211 shown in FIG. 3)coupled to splice plates 212 to move longitudinally. FIG. 7 is a topplan view of a fork bar 232 and a splice plate 212. In the illustratedembodiment, fork bar 232 includes a first channel 234 and a secondchannel 236 narrower than first channel 234. In other embodiments, forkbar 232 may include a different number of channels or a differentconfiguration of channels. Splice plate 212 includes one or moreretaining structures 238. In the example embodiment, retainingstructures 238 are raised structures configured to limit the movement ofsplice plate 212 relative to busbar 230. In the illustrated embodiment,splice plate 212 includes one retaining structure 238 positioned withinfirst channel 234 and another retaining structure 238 positionedexternal of first and second channels 234, 236. First channel 234,second channel 236, and retaining structure 238 are sized such thatretaining structure 238 is movable within first channel 234 but cannotpass through second channel 236. Second channel 236 is configured tolimit the movement of the movable assemblies to a length of firstchannel 234.

In the illustrated embodiment, first channel 234 has a width W₁ greaterthan a width W_(r) of retaining structure 238 while second channel 236has a width W₂ less than width W_(r) of retaining structure 238. Assplice plate 212 moves outwardly from busbar 230, retaining structure238 within first channel 234 engages fork bar 232 at second channel toprevent further outward movement of splice plate 212. Similarly, movingsplice plate 212 inwards towards busbar 230 causes retaining structure238 external of channels 234, 236 to engage fork bar 232 at secondchannel 236 to prevent further inward movement. Additionally oralternatively, retaining structure 238 within first channel 234 mayengage fork bar 232 at an end opposite of second channel 236 to limitmovement.

In the example embodiment, splice plate 212 further includes a rib 240that extends longitudinally on splice plate 212. Rib 240 is configuredto pass through first and second channels 234, 236. Rib 240, whenconnecting a rib 240 from another splice plate 212, enables splice plate212 to transfer and distribute a compressive force, such as thecompressive force provided by bracing fasteners 226 shown in FIG. 5. Ifthe compressive force is not distributed, components impacted by thecompressive force may be damaged.

FIGS. 8 and 9 are cross sectional views of splice plates 212 when acompressive force is applied. As shown in FIG. 8, when fork bars 232 arepositioned within splice plates 212, the force is distributed andtransferred through fork bars 232. In the example embodiment, spacers(e.g., spacers 216, shown in FIG. 3) adjacent to fork bars 232 alsotransfer the compressive force. When fork bars 232 have moved away fromrib 240 as shown in FIG. 9, the pair of ribs 240 is configured totransfer the compressive force. In the example embodiment, each rib 240has a height H_(r) approximately half of a height H_(b) of fork bars 232such that pairs of ribs 240 contact each other.

With reference again to FIG. 3, braces 250 are configured to supportbusbars 230 while maintaining separation between adjacent busbars 230 toprevent short circuit events and damage to busway joint 200 if a shortcircuit event occurs. In some embodiments, braces 250 are formed from ametal such as iron, aluminum, or steel. Additionally or alternatively,braces 250 may be formed using an insulative material such as plastic orrubber. Although three braces 250 are shown in FIG. 3, it is to beunderstood that busway joint 200 may include a different number ofbraces 250 (including one).

Braces 250 are slidably coupled to busbars 230 to enable braces 250 tomove based on movable assemblies 210, 211. In at least some embodiments,braces 250 include one or more stationary braces 252 that are fixedlycoupled to busbars 230. In the example embodiment, each brace 250includes a plurality of laminations 254 to support and separate busbars230. In other embodiments, braces 250 do not include laminations 254 andimplement a different configuration to couple to busbars 230, such asintegrated slots (not shown). In the illustrated embodiment, each busbar230 is disposed between two laminations 254. Braces 250 may be securedaround busbars 230 using one or more fasteners (e.g., bolts, screws,pins, etc.). Alternatively, braces 250 may be secured around busbars 230using a different technique or component.

In the example embodiment, when movable assemblies 210, 211 are movedoutward with respect to busway joint 200, braces 250 (with the exceptionof stationary brace 252) move outwardly to support busbars 230. Braces250 may spread apart up from each other and movable assemblies 210, 211up to a predetermined distance or interval. To prevent braces 250 fromspreading apart beyond the predetermined interval, busway joint 200 mayinclude one or more brace locators (not shown in FIG. 3) thatself-adjust braces 250. The brace locator is configured to positionbraces 250 at the predetermined interval until movable assemblies 210,211 are moved inwardly. In one embodiment, the brace locator positionsbraces 250 at the predetermined interval when movable assemblies 210,211 are in the expanded position. In the example embodiment, movablebraces 250 include a slot 256 to receive a brace locator. In someembodiments, the brace locator is a rigid member such as, for example, arod, bracket, or a plate. Alternatively, the brace locator may be aflexible member such as a spring or another flexible material. Theflexible member is configured to bias braces 250 within thepredetermined interval.

In certain embodiments, the brace locator is coupled to movableassemblies 210, 211. Additionally or alternatively, the brace locatormay be coupled to stationary brace 252. The brace locator may be coupledto multiple braces 250. For example, the brace locator may be configuredto telescope with each coupled brace 250.

FIGS. 10-12 illustrate a partial perspective view of another examplebusway joint 300 with different brace locator configurations. Buswayjoint 300 is similar to busway joint 200 (shown in FIG. 3) and, in theabsence of contrary representation, includes similar components. Buswayjoint 300 includes a movable assembly 310, conductors 330, a movablebrace 350, and a stationary brace 352. Movable assembly 310 includes acover 318. In the example embodiment, brace 350 includes a pair offasteners 358. In other embodiments, brace 350 may include a differentnumber of fasteners 358.

With reference to FIG. 10, busway joint 300 includes an example bracelocator 360 coupled to cover 318 and fasteners 358 of brace 350. Bracelocator 360 includes a pair of brackets that couple to the top andbottom of fasteners 358. Brace locator 360 includes tabs 362 that arepositioned within a corresponding channel 364 of cover 318. As movableassembly 310 moves outward, tabs 362 slide through channel 364 untiltabs 362 engage cover 318 at the end of channel 364. Brace 350 isconfigured to move with brace locator 360. In the example embodiment,the distance between movable assembly 310 and brace 350 is limited by alength L_(c) of channel 364. Once tabs 362 engage cover 318, brace 350may continue to extend outward with movable assembly 310, but bracelocator 360 is configured to prevent the distance between movableassembly 310 and brace 350 from increasing.

Busway joint 300 shown in FIG. 11 includes another example brace locator370. In the illustrated embodiment, brace locator 370 is a slidableT-shaped bracket that includes tabs 372. Cover 318 includes a gap 374.Brace locator 370 is positioned within gap 374. In the exampleembodiment, tabs 372 have a width W_(b) that is greater than a widthW_(g) such that tabs 372 are prevented from passing through gap 374.Tabs 372 engage cover 318 to prevent the distance between movableassembly 310 and brace 350 from increasing. In the example embodiment,the distance between movable assembly 310 and brace 350 is limited basedon a length L_(b) of brace locator 370.

Busway joint 300 shown in FIG. 12 includes another example brace locator380. Brace locator 380 includes a pair of slidable rods 382 coupled tobrackets that are attached to fasteners 358. In some embodiments, rods382 include a stopping member (not shown) configured to engage cover 318and prevent further movement of brace 350 relative to movable assembly310. The stopping member may include, for example, a bolt, a nut, awasher, an insert, a spring, a flexible component, or a bracket. Thestopping member may be coupled to rods 382 or integrally formed. In theexample embodiment, brace locator 380 includes a bracket 384 similar tobrace locator 360 shown in FIG. 10 to prevent the distance betweenmovable assembly 310 and brace 350 from increasing. Rods 382, with orwithout a stopping member, are configured to linearly guide busway joint300 as movable assembly 310 is extended or contracted. In someembodiments, rods 382 may telescope to extend the length of rods 382.

In the example embodiment, cover 318 includes a pair of slots 386. Rods382 are slidably coupled to cover 318 through slots 386. In someembodiments, slots 386 have a diameter greater than an outer diameter ofrods 382 but smaller than a diameter of a stopping member. In suchembodiments, the distance between movable assembly 310 and brace 350 maybe limited to a length between the stopping member and brace 350.

Although FIGS. 10-12 illustrate busway joint 300 with brace 350 coupledto cover 318 and stationary brace 352 positioned adjacent to brace 350,it is to be understood that brace locators may be used in differentconfigurations. For example, the brace locator may be coupled tostationary brace 352 or a second brace 350 to prevent a distance betweena first brace 350 and stationary brace 352 or a second brace 350 fromincreasing. In another example, busway joint 300 may include a differentconfiguration for cover 318 and the brace locator that limits thedistance between movable assembly 310 and brace 350. In yet anotherexample, the brace locator may be coupled to a plurality of adjacentbraces 350. In the example, the brace locator may be configured tolimits the distance between each brace 350.

FIG. 13 illustrates a top perspective view another example busway joint400 for use in a busway system, such as busway system 110 shown inFIG. 1. Busway joint 400 is similar to busway joint 200 (shown in FIG.3) and, in the absence of contrary representation, includes similarcomponents. In the example embodiment, busway joint 400 includes a pairof opposed movable assemblies 410, 411, a stationary assembly 420, aplurality of busbars 430, and an adjustment assembly 440. In otherembodiments, busway joint 400 may include additional, fewer, oralternative components to electrically couple busway sections, includethose described elsewhere herein.

Busway joint 400 is configured to selectively adjust its length tocouple to at least two spaced apart busway sections. Selectivelyadjusting the length of busway joint 400 facilitates use of busway joint400 for different distances between busway sections. Although buswayjoint 400 is shown as a longitudinally extending joint, busway joint 400may have a different configuration (e.g., an elbow joint, an anglejoint, etc.).

Movable assemblies 410, 411 are configured to move to adjust the lengthof busway joint 400. In the example embodiment, movable assemblies 410,411 are coupled to busbars 430. Each busbar 430 is divided, for example,in half for each phase such that one portion of busbar 430 moves withmovable assembly 410 and another portion of busbar 430 moves withmovable assembly 411.

Movable assemblies 410, 411 include a cover 412 to support busbars 430.In the example embodiment, covers 412 substantially surround a portionof busbars 430. Covers 412 are configured to prevent contaminants fromaffecting the interior of movable assemblies 410, 411. In theillustrated embodiment, movable assembly 411 further includes a guard414 coupled to cover 412 for protecting and maintaining an interfacebetween busway joint 400 and a busway section.

Stationary assembly 420 is disposed between movable assemblies 410, 411.Movable assemblies 410, 411 surround stationary assembly 420. Stationaryassembly 420 is configured to support and protect busbars 430 and spliceplates (not shown in FIG. 13) within busway joint 400. In the exampleembodiment, stationary assembly 420 includes a pair of covers 421coupled together around busbars 430 and the splice plates. Stationaryassembly 420 includes a plurality of support structures 422 to couplecovers 421 together. Each support structure 422 includes one or morefasteners that extend through apertures (not shown) in stationaryassembly 420 to another support structure 422. In other embodiments,stationary assembly 420 may include a different number and/orconfiguration of covers 421. For example, stationary assembly 420 may beintegrally formed.

Adjustment assembly 440 is coupled to movable assemblies 410, 411.Although adjustment assembly 440 is shown in FIG. 13 coupled to one sideof busway joint 400, adjustment assembly 440 may be in a differentposition. Additionally or alternatively, busway joint 400 may include aplurality of adjustment assemblies 440. For example, one adjustmentassembly 440 may be configured to position movable assembly 410 andanother adjustment assembly 440 may be configured to position movableassembly 411. Adjustment assembly 440 is configured to selectivelyextend or contract movable assemblies 410, 411 to a predeterminedposition to connect a pair of busway sections. In the illustratedembodiment, adjustment assembly 440 is coupled to cover 412 via abracket. Adjustment assembly 440 may include, for example, a gear, apinion, one or more gear racks, a lever, and/or other components thatenable an operator to selectively extend or contract busway joint 400.

FIG. 14 depicts an exploded view of adjustment assembly 440. In theexample embodiment, adjustment assembly 440 includes a pair of opposedcovers 442, 443, a gear 444, a pair of opposed gear racks 446, 447, anda pair of caps 448. In other embodiments, adjustment assembly 440 mayinclude additional, lesser, or alternative components for adjustingmovable assemblies 410, 411 (shown in FIG. 13).

Covers 442, 443 are configured to protect gear 444 and gear racks 446,447 from contaminants. Caps 448 are configured to secure covers 442, 443together. Covers 442, 443 include apertures and channels for gear 444and gear racks 446, 447. Gear 444 is operatively coupled to gear racks446, 447. In the example embodiment, gear rack 446 is coupled to movableassembly 410 and gear rack 447 is coupled to movable assembly 411. Inother embodiments, adjustment assembly 440 may include a scissor rack.Gear racks 446, 447 include apertures, fasteners, hooks, or other matingcomponents to couple to movable assemblies 410, 411. Gear 444 isconfigured to selectively rotate. For example, an operator may rotategear 444 with a tool. Rotating gear 444 causes gear racks 446, 447 (andmovable assemblies 410, 411) to move longitudinally towards or away fromeach other. Covers 442, 443 include channels for each gear rack 446, 447to limit the longitudinal movement. In particular, gear racks 446, 447are limited between an expanded position and a collapsed position. Insome embodiments, adjustment assembly 440 may include a shear pin orother component to limit gear racks 446, 447 to the expanded position.

In one example, when installing busway joint 400 (shown in FIG. 13) withadjustment assembly 440 in a busway system between two spaced apartbusway sections, an operator rotates gear 444 to extend movableassemblies 410, 411 towards the busway sections. When movable assemblies410, 411 are coupled to the busway sections, the operator secures buswayjoint 400 in position. In at least some embodiments, adjustment assembly440 may include one or more locking pins, levers, or other components toprevent gear racks 446, 447 (and movable assemblies 410, 411) frommoving.

FIG. 15 illustrates a side perspective view of busway joint 400. Covers412 and stationary assembly 420 have been removed for clarity. In theexample embodiment, busway joint 400 includes a plurality of spliceplates 432, insulation laminations 434, and insulative spacers 436.

Splice plates 432 extend through stationary assembly 420 and may extendthrough a portion of movable assemblies 410, 411. Splice plates 432,similar to splice plates 212 shown in FIG. 3, are electrically coupledto busbars 430. Splice plates 432 are configured to maintain electricalconnection to busbars 430 even when busbars 430 have been extended withmovable assemblies 410, 411. Splice plates 432 are vertically stackedwith busbars 430 and insulation laminations 434. Insulation laminations434 are configured to electrically isolate busbars 430 from each otherto prevent short circuit events. In certain embodiments, splice plates432 are configured to move with movable assemblies 410, 411. In suchembodiments, busbars 430 may not move with movable assemblies 410, 411.

Spacers 436 are configured to space splice plates 432 apart to receivebusbars 430 and insulation laminations 434. In the illustratedembodiment, supporting structures 422 include spacers 436. In theexample embodiment, busway joint 400 also includes one or more visebraces 450 to selectively clamp busbars 430 and prevent movableassemblies 410, 411 from further movement. Vise braces 450 also includespacers 436. In the illustrated embodiment, busway joint 400 includes apair of vise braces 450. In other embodiments, busway joint 400 mayinclude a different number of vise braces, such as one, three, or fourvise braces 450. Vise braces 450 are externally coupled to busbars 430and splice plates 432. Vise braces 450 are adjustable to apply acompressive force on busbars 430, splice plates 432, insulationlaminations 434, and/or spacers 436. In one example, when installingbusway joint 400 in a busway system between two spaced apart buswaysections, movable assemblies 410, 411 are adjusted to couple to thebusway sections. Vise braces 450 are then adjusted to apply thecompressive force and secure busway joint 400 in place.

With reference to FIGS. 16 and 17, vise braces 450 are furtherdescribed. FIG. 16 is a side perspective view of busway joint 400. FIG.17 is a cross sectional perspective view of vise brace 450. In theexample embodiment, vise brace 450 includes a clamp screw 452, a frame454, one or more fasteners 458, and a compressive washer 460. In otherembodiments, vise brace 450 may include additional, fewer, oralternative components to secure busbars 430 and splice plates 432together.

In the example embodiment, clamp screw 452 is configured to selectivelyprovide a compressive force to couple busbars 430 and splice plates 432together. Clamp screw 452 is threaded such that rotating clamp screw 452increases or decreases the compressive force. In the example embodiment,rotating clamp screw 452 clockwise increases the compressive force whilerotating clamp screw 452 counter-clockwise decreases the compressiveforce. Alternatively, rotating clamp screw 452 clockwise may decreasethe compressive force and rotating clamp screw 452 counter-clockwise mayincrease the compressive force. In comparison, some known busway jointsuse a bolt that extends through the busbars and/or the splice plates tosecure the busway joint. The bolt may reduce the cross sectional area ofthe busbars and the splice plates and create a dielectric gap betweenadjacent busbars. Current may travel across the dielectric gap and causea short circuit event. In contrast, the compressive force provided byclamp screw 452 secures busway joint 400 without creating a dielectricgap between adjacent busbars 430.

Clamp screw 452 is externally accessible on busway joint 400 to enablean operator to adjust the compressive force. As shown in FIG. 16, clampscrew 452 is accessible on the opposite side of busway joint 400 fromadjustment assembly 440 (shown in FIG. 13). Although vise brace 450 isshown with one centrally located clamp screw 452, vise brace 450 mayinclude a different number of clamp screws 452 and/or clamp screws 452in a different location.

Frame 454 includes a top brace 456 and a bottom brace 457 coupledtogether by fasteners 458. In the illustrated embodiment, fasteners 458extend through spacers 436. Alternatively, fasteners 458 may extendaround spacers 436 to couple braces 456, 457 together. Frame 454 isexternally coupled around busbars 430 and splice plates 432. In theexample embodiment, the compressive force is applied by clamp screw 452towards bottom brace 457. Busbars 430 and splice plates 432 arecompressed between clamp screw 452 and bottom brace 457. In otherembodiments, the compressive force is applied towards top brace 456. Inthe example embodiment, fasteners 458 extend through spacers 436. Incertain embodiments, fasteners 458 may provide a portion of thecompressive force similar to bracing fasteners 226 (shown in FIG. 4).Fasteners 458 are configured to permit busbars 430 and/or splice plates432 to move through vise brace 450 when clamp screw 452 is not providingthe compressive force.

Compressive washer 460 is coupled between clamp screw 452 and busbars430 to distribute the compressive force. In the illustrated embodiment,compressive washer 460 is a conical washer. Alternatively, compressivewasher 460 may be a different shape. In the example embodiment,compressive washer 460 has a raised or curved surface. As clamp screw452 is rotated and the compressive force is increased, the compressiveforce causes washer 460 to flatten and distribute the compressive force.In some embodiments, compressive washer 460 is integrally formed withclamp screw 452. In other embodiments, vise brace 450 does not includewasher 460.

In the illustrated embodiment, busway joint further includes acompressive plate 462 that extends through each vise brace 450 along alength of busbars 430 and splice plates 432. Compressive plate 462 isconfigured to distribute a cumulative compressive force from vise braces450.

The exemplary embodiments of an adjustable busway joint, a buswaysystem, and a method of installing the adjustable busway joint aredescribed above. The adjustable busway joint facilitates coupling buswaysections at different offset distances without requiring a fixed-lengthbusway joint at a specific offset distance. Slidably coupling busbarsand splice plates within the busway joint enables the busway joint toextend longitudinally while maintain an electrical connection. Otherfeatures and components described in the exemplary embodimentsfacilitate longitudinal extension of the busway joints and securing thebusway joint in a particular position.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A busway system comprising: a first electricalbusway section; a second electrical busway section, said first and saidsecond electrical busway sections disposed longitudinally offset fromeach other; and a busway joint coupling said first and said secondbusway sections, said busway joint comprising: a first assembly coupledto said first busway section; a second assembly coupled to said secondbusway section, said first and said second assemblies configured to moverelative to each other between a collapsed position and an extendedposition; a plurality of conductors coupled to said first and saidsecond assemblies; a first movable brace positioned between said firstassembly and said second assembly, wherein said first movable brace iscoupled to said plurality of conductors and is configured to movelongitudinally along a length of said plurality of conductors; and afirst brace locator coupled to said first movable brace, said firstbrace locator configured to locate said first movable brace at a firstposition when said first assembly is in the extended position.
 2. Thebusway system of claim 1, wherein said busway joint further comprises: asecond movable brace coupled to said plurality of conductors; and asecond brace locator coupled to said second movable brace, said secondbrace locator configured to locate said second movable brace at a secondposition when said second assembly is in the extended position.
 3. Thebusway system of claim 2, wherein said busway joint further comprises astationary brace coupled to said plurality of conductors between saidfirst and said moveable second braces.
 4. The busway system of claim 3,wherein said first brace locator is coupled to said stationary brace. 5.The busway system of claim 1, wherein said busway joint furthercomprises a third movable brace coupled to said plurality of conductorsand said first brace locator, said first brace locator configured tolocate said third movable brace at a third position spaced from thefirst position.
 6. The busway system of claim 1, wherein said firstmovable brace is substantially adjacent to said first assembly when saidfirst assembly is in the collapsed position.
 7. The busway system ofclaim 1, wherein said first brace locator is a rigid member slidablycoupled to said first assembly.
 8. The busway system of claim 7, wheresaid first brace locator is at least one of a rod and a bracket.
 9. Thebusway system of claim 1, wherein said first brace locator is a flexiblemember configured to locate said first movable brace at the firstposition when said first assembly is in the extended position.
 10. Thebusway system of claim 1, wherein said first movable brace comprises: aplurality of laminations, wherein each conductor of said plurality ofconductors is coupled between a pair of said plurality of laminations;and at least one clamping member configured to clamp said plurality oflaminations and said plurality of conductors together.
 11. A buswayjoint coupling a first busway section and a second busway section, saidbusway joint comprising: a first assembly coupled to the first buswaysection; a second assembly coupled to the second busway section, saidfirst and said second movable assemblies configured to move relative toeach other between a collapsed position and an extended position; aplurality of conductors coupled to said first and said secondassemblies; a first movable brace positioned between said first assemblyand said second assembly, wherein said first movable brace is coupled tosaid plurality of conductors and is configured to move longitudinallyalong a length of said plurality of conductors; and a first bracelocator coupled to said first movable brace, said first brace locatorconfigured to locate said first movable brace at a first position whensaid first assembly is in the extended position.
 12. The busway joint ofclaim 11 further comprising: a second movable brace coupled to saidplurality of conductors; and a second brace locator coupled to saidsecond movable brace, said second brace locator configured to locatesaid second movable brace at a second position when said second assemblyis in the extended position.
 13. The busway joint of claim 12 furthercomprising a stationary brace coupled to said plurality of conductorsbetween said first and said second movable braces.
 14. The busway jointof claim 13, wherein said first brace locator is coupled to saidstationary brace.
 15. The busway joint of claim 11 further comprising athird movable brace coupled to said plurality of conductors and saidfirst brace locator, said first brace locator configured to positionsaid third movable brace at a third position spaced from the firstposition.
 16. The busway joint of claim 11, wherein said first movablebrace is configured to be substantially adjacent to said first assemblywhen said first assembly is in the collapsed position.
 17. The buswayjoint of claim 11, wherein said first brace locator is a rigid memberslidably coupled to said first assembly.
 18. The busway joint of claim17, where said first brace locator is at least one of a rod and abracket.
 19. A method for assembling a busway system that includes afirst busway section, a second busway section disposed longitudinallyoffset from the first busway section, and a busway joint, said methodcomprising: coupling the first busway section to a first assembly of thebusway joint, the busway joint movable between a collapsed position andan extended position; adjusting a length of the busway joint, wherein abrace locator of the busway joint is configured to locate a movablebrace of the busway joint positioned between the first assembly and asecond assembly of the busway joint at a first position when the buswayjoint is in the extended position; and coupling the second buswaysection to the second assembly of the busway joint.
 20. The method ofclaim 19, wherein adjusting the length of the busway joint furthercomprises sliding the movable brace along a plurality of conductors.